Gate locking device featuring dead bolt means
This is a continuation-in-part application of Ser. No. 07/310,349, filed Feb. 13, 1989, now issued as U.S. Pat. No. 4,919,463. The entire disclosure of this application is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a gate lock for a chain link fence, and more particularly, to a high security gate lock for chain link fences. 
     2. Prior Art 
     Chain link fences are well known. Typically such fences include a frame having numerous poles disposed at fixed intervals which support a mesh of thick metal wire which forms a screen. The screen is secured to the poles by pieces of wire. To provide a gate in an opening between two poles of a chain link fence, the gate being about the size of the opening is hinged to a pole on one side of the opening. An oarlock or fork latch is hingeably attached to the opposite pole of the gate frame. When the gate is in the closed position, the oarlock or fork latch is moved to the horizontal position where it receives the pole o the fence in the U-shaped portion thereof. 
     To lock the gate when the oarlock is in the closed position, i.e. horizontal, openings in the lock and collar are provided which line up, and a padlock is passed through the openings to lock them in their aligned position. With the lock in place, the oarlock cannot be moved from the horizontal closed position to the vertical open position. Thus the gate is locked. 
     The drawbacks of such a method of locking a chain link gate includes difficulty in opening and closing the lock and gate, the potential to lose or misplace the lock, and the inherent weakness of an oarlock or fork latch to tampering by an intruder. Loss of the lock occurs frequently because the padlock has to be removed from the gate to complete the locking and unlocking operation. Further, in order to unlock the gate two hands must be used, one hand to hold and steady the lock and another hand for inserting the key to open the lock. 
     U.S. Pat. No. 4,691,541 to the inventor herein, McQuade (hereinafter &#34;McQuade &#39;541&#34;) eliminates the risk of losing or misplacing the lock because the locking device is always attached to the gate frame. At no time is the lock removed from the gate to complete its operation. Operational ease is attained because the lock is stationary and the key slot is accessible. To open the lock simply insert the key and turn. When the key is turned, the lock cylinder will pop out and release the lock bar from the oarlock. To lock the gate, the oarlock is moved to its horizontal, locking position and a push button cylinder is engaged to move its lock bar into an opening in the oarlock to fix the oarlock in position. 
     In McQuade &#39;541 the collar holding the lock and oarlock is modified from that typically used to retain an oarlock. The collar is in two pieces and sandwiches the pipe of the gate frame. Set screws pass through the collar causing the collar to engage the trame pipe. The lock system is comprised of several parts, and each of the parts is easily replaceable permitting quick repair. The lock provides a child proof gate lock with ease of installation. The lock is always in its proper locking position and cannot be misplaced. 
     The McOuade &#39;541 gate lock works very well for its intended use as a low security gate lock, but the locking mechanism can be pulled out of the gate lock assembly by one who wishes to breach the security of the chain link fence. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     An object of the invention is to provide a gate locking device for chain link fences which is a high security locking device. 
     Another object of the invention is to provide a gate locking device for chain link fences which has a positive locking action of a dead bolt means. 
     Another object of the invention is to provide a gate locking device for chain link fences which is easily locked and unlocked. 
     Another object of the invention is to provide a gate locking device for chain link fences which is retrofittable on existing chain link fences. 
     Accordingly, the gate locking device for a fence having first and second poles comprises: (a) a security box; (b) means for mounting the security box to the first pole of the fence; (c) oarlock means mounted to the security box having an oarlock, the oarlock being moveable between an unlocked position and a locked position where the oarlock receives the second pole of the fence; (d) dead bolt means affixed to the security box having a dead bolt being moveable between an extended and unextended position, when in the extended position the dead bolt substantially prevents movement of the oarlock mean; and (e) a barrel lock mounted to the security box and mechanically connected to the dead bolt and adapted for moving it, whereby when the oarlock is moved to the locked position and the dead bolt is extended the gate is securely locked to prevent unauthorized intrusion. 
     In a preferred embodiment the oarlock means is hingeably mounted to the box, and when the oarlock is moved to the locked position and the dead bolt is moved to the extended position, it substantially prevents the pivotal movement of the oarlock means back to the unlocked position. 
     In an alternative embodiment the oarlock means is slidably mounted to the security box, and when the oarlock is moved to the locked position and the dead bolt is moved to the extended position, it substantially prevents the slideable movement of the oarlock means back to the unlocked position. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES IN THE DRAWING 
     A more complete understanding of the invention may be had by reference to the accompanying drawing illustrating embodiments of the invention in which like reference numeral characters refer to like parts throughout the several views and in which: 
     FIG. 1 is a front perspective view of the device of the invention; 
     FIG. 2 is a side view of the invention shown in FIG. 1; 
     FIG. 3 is a top view of the invention shown in FIG. 2; 
     FIG. 4 is a perspective view of a second embodiment of the invention shown in FIG. 1; 
     FIG. 5 is a side view of the embodiment shown in FIG. 4; 
     FIG. 6 is another side view of the invention shown in FIG. 4; 
     FIG. 7 is a cross-sectional view of the embodiment shown in FIG. 5 along lines 7--7 therein; 
     FIG. 8 is an exploded view of the embodiment shown in FIG. 4. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in FIGS. 1, 2 and 3, numeral 10 denotes generally, the gate lock disclosed and claimed in the McQuade &#39;541 which is incorporated herein by reference. The lock 10 is mounted on gate poles or pipes 12 and 14. However, the present invention does not have the locking arrangement described in McQuade &#39;541. The present invention is usable with any gate lock arrangement, but preferably with a gate lock that employs an oarlock or fork latch of the general type shown in McQuade &#39;541. Oarlocks of this type are well known in the art. 
     As shown in FIGS. 1, 2 and 3, a &#34;U&#34; shaped collar 16 is mounted on and surrounds a gate pipe 18. Collar fixture 16 has bolt apertures 20 and 22 formed therein and also has a threaded screw aperture 24 formed therein. Bolt apertures 20 and 22 permit the end portions 26 and 28 of collar 16 to be bolted one to the other (a bolt 30 is shown in FIG. 3). The threaded screw aperture 24 permits additional security by tightening a screw 32, shown in FIG. 3, in aperture 24, preferably into gate pipe 18, to secure further the collar 16 to pipe 18. 
     Collar 16, thus secured to the gate pipe 18, has two housings 34 and 36 formed at opposite ends of the collar 16. These housing portions, 34 and 36, each have a bottom surface which contains an aperture 38 and 40 respectively, therein. Two pairs of side walls (42, 44 in housing 34, and 46, 48 in housing 36) are provided to complete the housing. 
     The apertures 38 and 40 and the side walls of the housings 34 and 36 cooperate with and partially enclose the sides 50 and 52 of oarlock 58 and tab portions 54 and 56 formed on said sides. 
     More specifically, the oarlock 58 is formed of a shape complementary to the shape of collar 16. Extended tabs 54 and 56 are found at each of the ends of the sides 50 and 52 of the oarlock 58. Only one such tab 54 is shown in FIGS. 1 and 2. The tab 54 is formed on the end of side 50 of the oarlock 58 and a corresponding tab 56 is formed on the end of side 52 of oarlock 58. The tabs 54 and 56 interfit into slots 38 and 40, respectively, in the bottom surface of the housings 34 and 36. 
     As will now be apparent, the security afforded at the gate lock pipe 18 by the collar fixture 16 and the tabbed oarlock 58 is greatly enhanced over that customarily employed in the prior art as represented by the oarlock 14 in McQuade &#39;541. First, the application of force and pressure on the gate in an attempt to loosen the lock by enabling the oarlock 58 to twist out of engagement with the pipe 18 is inhibited by tabs 54 and 56 interfitting into slots 38 and 40 within the side walls of protective housings 34 and 36. Further, the tabs 54 and 56 interfit within the slots 38 and 40 and the side walls of the housings 34 and 36 and inhibit the ability of the oarlock to be twisted out of engagement with the gate pipe 14. 
     Secondly, the side walls 42, 44 and 46, 48 of the housings 34 and 36 also inhibit access to the point of connection of the tabs 54 and 56 on the oarlock 58 within the slots 38 and 40 of the housings 34 and 36. Any attempt to utilize a screw driver or other tool to gain leverage by forcing the screw driver or tool into the top of the housings 34 or 36 to force the screw driver underneath the oarlock 58 and thereby out of the slots 38 and 40, is impossible by virtue of the protective surfaces provided by the side walls 42, 44 and 46, 48. 
     Thirdly, attempts to bend an arm of the oarlock 58 to widen the opening in the oarlock 58 will be frustrated by the walls of the protective housings 34 and 36 surrounding the sides 50 and 52 of the oarlock. 
     Another embodiment of this invention is shown in FIG. 4, wherein a security box 100 has affixed thereon a mounting bracket 110 with carriage bolts 111 fastening it to pole 14. An oarlock 130 is shown in the horizontal locking position and is pivotally connected within the security box moveable between an unlocked and a locked position. This movement is accomplished manually by handles 132. As shown, a slot in the security box allows the oarlock 130 to extend through the security box. For the purpose of discussing the alternative embodiment oarlock 130 (FIG. 4) is substantially similar to the oarlock 58 (FIGS. 1-3) previously described. 
     As shown in FIGS. 5 and 6, a lock means is shown as a barrel-type lock mechanism 120 extending from an aperture of the security box 100. As one skilled in the art would appreciate, in operation a key is inserted and turned between an unlocked and locked position. A dead bolt means 140 shown in phantom is connected to the barrel lock 120 by mechanical linkage 144 and its dead bolt 142 moves between an extended position (FIG. 5) and unextended position (FIG. 6) in response to the barrel locking mechanism 120. 
     The oarlock 130 is pivotally connected within the security box 100 by pin 160 and has a heel plate 136 extending therefrom which is maintained in close proximity to the dead bolt 142. In operation when the oarlock 130 is in the locked horizontal position, as shown in FIG. 5, and the dead bolt 142 is extended, the oarlock 130 is locked downwardly because any lifting upwardly of the oarlock 130 is prevented when the heel plate 136 contacts the dead bolt 142. As shown, the heel plate 136 contacts the side of the dead bolt 142. The oarlock may also be locked in the upward position in FIG. 6 if the dead bolt is extended (not shown). In an alternative embodiment, as one skilled in the art would appreciate, the dead bolt 142 may also be disposed to the right side of the pivot pin 160, and adapted so as to work equally as well (not shown). 
     As shown in FIG. 6 the barrel lock means 120 has been turned counterclockwise as shown by the arrow from that of FIG. 5, and the dead bolt 142 is now in its unextended position so that when the oarlock 130 is lifted to its unlocked position heel plate 136 is free to move past the dead bolt 142. 
     FIG. 7 shows a specific embodiment of the assembly inside the security box 100. As shown the oarlock 130 is pivotally attached to U brackets 170 and 172 by pin 160 having cotter pins 162 therein. The U brackets 170 and 172 are welded to plate 148 and plate 148 is itself welded to 100 at points 101. The dead bolt 142 is shown disposed to the left side of the pivot pin 160. The dead bolt means 140 is affixed to plate 142 by screw means 141 (see also FIG. 8 herein) and linkage 144 is shown mechanically connecting barrel lock means 120 to the dead bolt means 140. Holes 180 and 181 are shown as screw holes to receive a plate 210 as described best in FIG. 8 below. 
     As shown in FIG. 8 security box 100 has aperture 104 passing therethrough and top surface slot 106 . The assembly of the barrel lock 120, dead bolt means 140 and unimolded bracket means 220 are slidably disposed within the security box and welded thereto as described herein. Cover plate 210 is then disposed on the securitY box with plate screws 212 and 213 being screwed into screw holes 180 and 181 respectively. Thereafter when the mounting means 110 is affixed to a pole (not shown), screws 2I2 and 213 are not reachable by one seeking to breach the integrity of the gate locking device. 
     In an alternative embodiment of the invention (not shown), the oarlock means may be slidably affixed to the security box, and when the dead bolt is moved to the extended position, it substantially prevents the slidable movement of the oarlock means. As one skilled in the art would appreciate, the heel plate can have one or more apertures therein for receiving the dead bolt in either the extended position, the unextended position, or both positions, to prevent unauthorized locking or unlocking of the gate. 
     The scope of the invention should not be limited by the particular shape of the oarlock, the particular angle of the heel plate, be it 0° , 90° or otherwise, or the particular number of apertures in the heel plate for receiving the dead bolt, since embodiments discussed herein may include no apertures, or one or more apertures. 
     The scope of the invention should also not be limited by the way the oarlock means is attached to the security box. For the purposes of description only, it is shown and described as being pivotally affixed to the inside of the box. But in other embodiments envisioned by the inventor, the gate locking device could work equally as well if it is pivotally attached to the outside of the box, as long as the dead bolt can be moved to a position where it substantially prevents any further movement of the oarlock means. 
     While the invention has been described in the preferred embodiment, it is to be understood that the words which have been used are words of description rather than limitation and that changes may be made within the purview of the appended claim without departing from the true scope and spirit of the invention in its broader aspects.